Operation rings, such as a focusing ring and a zoom ring, are rotatably provided around the outer periphery of the main body of a lens barrel of a surveillance camera which involves manual focusing operation, manual zooming operation, and the like. Focusing or zooming is performed by means of rotationally operating the operation ring (see, e.g., JP-A-2004-54186).
The lens barrel having such operation rings is provided with rotation regulation means for regulating rotational ranges of the operation rings. The rotation regulation means is formed from, e.g., a rotation regulatory pin projectingly provided on the operation ring, and a groove for the main body of the barrel with which the pin is engaged. As a result of the pin coming into contact with the end of the groove, the rotational range of the operation ring is regulated. The pin for use in regulating rotation is usually formed into a self-tapping screw. The pin is fastened as a result of being screwed into the operation ring made of resin.
However, the related-art lens barrel has the potential risk of the rotation regulation pin being fixed in an inclined manner when the pin is inserted into the operation ring. When the pin is fixed in an inclined manner, the operation angle of the operation ring becomes inaccurate, and there arises a problem of focusing or zooming being adversely affected.
Since the related-art lens barrel requires the rotation regulatory pin and the groove, there exists a problem of the lens barrel becoming bulky or an increase arising in the cost of the lens barrel.